Phylogeny and Classification of World Hydropsychidae, with a Revision of Chinese Species and Description of Their Larvae

Clemson University, Clemson SC

Investigators

Abstract

With 1462 species in 52 genera, the cosmopolitan family Hydropsychidae is one of the most-speciose families of caddisflies (Trichoptera). Although the Oriental Region is one of the world's most unexplored, about one-third of all described caddisfly species occur there. Hydropsychids are the most commonly encountered caddisflies in Asian streams. In their role as predators and collecting-filterers, larval hydropsychids are key components for the processing of nutrients in stream ecosystems and they govern the densities of many prey, host, and predator species in those ecosystems. Larvae of species in the family are very important as subjects of biomonitoring efforts because they display a wider range of tolerances for pollution than almost every other family of aquatic insects and occur in samples of benthic organisms from all but the most polluted streams. Poor water quality is a very serious problem in Southeast Asia. We will organize the classification of the Hydropsychidae of China, reviewing the known fauna and describing the many species awaiting description and those to be captured on expeditions. It is important to be able to identify (associate) larvae, because the immature stages are the ones that are exposed to pollution. We will associate and describe larvae of Chinese hydropsychids. We will infer the relationships among world genera and revise the family-group classification of the family. This project will be accomplished primarily by a PhD student in each of three laboratories: Mr. Sun Chianghai at Nanjing Agricultural University, Mr. Zhou Xin at Rutgers University, and Ms. Christy Jo Geraci at Clemson University. These three students will cooperate intensively. Mr. Sun will review known Chinese species, describe the new species currently on hand, and describe additional new species captured during two 30-day expeditions he will lead to Guangdong, Guangxi, and Fujian Provinces in China. Using DNA sequences from specimens collected on these expeditions and coordinated projects, Mr. Zhou will associate yet-unidentifiable larvae with identifiable adults and describe the associated larvae. Ms. Geraci will review previous and new morphological characters of all world genera. Then, using DNA sequences from specimens already in hand, together with sequences of specimens collected in China and obtained with assistance of colleagues in Australia, Thailand, New Zealand, New Caledonia, Malaysia, South Africa, and Brazil, she will infer relationships among world hydropsychid genera (on which classification is based) from combined-data. We expect at least to double the number of species of hydropsychids in China known to science. By describing the yet-unknown larvae of many hydropsychid species, we will lay the foundation for future ecological research and biomonitoring refinement in and around China. Research globally in this family will be facilitated conceptually by the phylogeny of world genera and resulting revision of family-group taxa that we will accomplish in this investigation. The proposed research advances discovery and understanding while training three Ph.D. scientists, two of whom are Chinese, the other a U.S. female. The research establishes partnerships between Rutgers and Clemson Universities and Nanjing Agricultural Universities and extends a highly productive 15-year partnership between Clemson and Nanjing that constitutes a widely respected model of Sino-American cooperation. Results will be disseminated broadly through professional publications and public media such as the World Wide Web and GenBank. Especially notable will be the extension of US-initiated technology to a rapidly deteriorating global problem of water pollution: results of this research will go a long way toward enabling effective biomonitoring of water pollution problems in China and refining understanding of a pollution-sensitive group of animals distributed globally, including the U.S.